Consumers increasingly rely on digital resources provided by electronic devices such as cellular telephones, digital cameras, or portable and handheld digital electronic devices. The increased quality and speed of digital data is becoming increasingly attractive to an ever-expanding consumer market, as has become evident in applications for wireless networks, downloadable digital music, digital movies, etc. Such applications demand rapid transmission of data.
One approach to rapidly transmitting data is direct sequence spread spectrum, also known as direct sequence code division multiple access (DS-CDMA). DS-CDMA is utilized in connection with cellular telephones, digital cameras, portable and handheld digital electronic devices, and other devices where a rapid data transmission rate is desired.
DS-CDMA is an approach to spread spectrum modulation for digital signal transmission. In DS-CDMA, a stream of data to be transmitted is divided into small pieces, each of which is allocated across to a frequency channel across the spectrum to provide a data signal. At the point of transmission, the data signal is combined with a higher data-rate bit sequence (also known as a chipping code) that divides the data according to a spreading ratio and provides redundancy.
Improvements are sought to increase not only the data rate but also the quality of transmissions.